Lamp socket for photoflash units



Marchglfs, 1955 D. M. PETERSON ETAL 3, 7

LAMP SOCKET FOR PHOTOFLASH UNITS Filed Aug. 20, 1962 Dean M.Peierson ChesivrWMichalelc IN V EN TORS' BY @MM WW x monnm United States Patent M 3,173,615 LAMP SOCKET FOR PHOTOFLASH UNITS Dean M. Peterson and Chester W. Michatek, Rochester,

N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Aug. 20, 1962, Ser. No. 217,829 4 Claims. (Cl. 240-15) The present invention relates to a photoflash unit for use in combination with photographic cameras, and particularly to an improved lamp socket for such a unit which is adapted to accommodate midget flash lamps of the type designated as AG-1.

Flash units having sockets capable of accommodating AG-l type flash lamps are generally well known, but they have possessed certain disadvantages. One of these has been the inability to securely hold the lamp in the socket in a stable and upright condition. This fault has generally been due to the fact that this type of lamp has a peculiar flattened base formed as a part of the lamp globe and which leaves little or no contiguous surface on the lamp which the socket might engage to accurately locate and stabilize the lamp in a given axial position. Furthermore, the peculiar shape of the base of these lamps makes it diflicult, if not impossible, to provide a latching means for positively holding the lamps in the socket, and the conventionally used frictional grip provided by the socket contacts has been opposed by a spring-loaded lamp ejecting means so that such arrangements have not been too satisfactory.

One object of the present invention is to provide a lamp socket for AG-l type flash lamps which is so constructed that it includes one or more parts, exclusive of the socket contacts, for engaging and supporting the globe of the lamp in such a way as to limit axial insertion of the lamp into the socket and thereafter stabilize the lamp in an erect position after it has been inserted into the socket.

Another object is to provide a lamp socket for AG-l type lamps which has no spring ejector which normally tends to push the lamp from the socket and which force the socket contacts must overcome in order to frictionally retain the lamp in the socket.

And a further object is to provide a lamp socket of the type described in which the ejection of the lamp from the socket is brought about by moving one socket contact relative to the other from a normal position wherein the two contacts frictionally retain the lamp in the socket to a lamp ejecting position during which movement the lamp base is squeezed from between the socket contacts and out of the socket in much the same manner in which a watermelon seed can be propelled when squeezed be tween the thumb and forefinger.

And yet another object is to provide a flash lamp socket of the type described which is extremely simple and inexpensive to manufacture and assemble by reason of the fact that it requires a minimum number of individual parts.

The novel features that we consider characteristic of our invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof will best be understood from the following description when read in connection with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view showing parts of a photoflash unit incorporating a lamp socket constructed in accordance with a preferred embodiment of the invention,

FIG. 2 is an enlarged sectional detail of the assembled socket, looking at it from the rear of the photoflash unit,

3,173fil5 Patented Mar. 16, 1965 and showing how the socket contacts of the flash unit might be connected into circuit relation with the flash synchronizing switch contained in the camera, and

FIG. 3 is a front elevational view of a conventional AG-l type flash lamp.

Since the lamp socket of the present invention has been designed particularly to accommodate AG-l type flash lamps, a knowledge of the configuration of the base portion of such lamps is deemed essential to a complete understanding of the present invention. Accordingly, while we have shown and will describe the configuration of the AG-l lamp we will not go into the internal construction or manufacturing technique used in the production of this lamp. Such information can be obtained from US. 2,982,119 which relates to this particular type of flash lamp.

Referring to FIGS. 2 and 3, the AG-l flash lamp comprises a sealed glass envelope or globe 10 approximately of tubular shape and consisting of a short length of drawn tubing closed at one end by an integral flattened stem press or base 12 which is elongate transversely of the axis of the lamp and has a rounded bottom as shown at 14. The tubular portion of the lamp is connected to the front and back sides of the base by tapered portions 16, see FIG. 2. The front and back sides of the stem press or base 12 are formed as flat surfaces preferably disposed substantially parallel to each other and to the axis of the lamp. The flat surfaces of the base are each provided with a transversely extending groove 18 for sliding engagement with cooperating guide track means of a lamp holding magazine or feeding chamber of a photoflash unit. Sealed into the base of the lamp is an ignition mount 20 comprising a pair of lead-in wires 21 which, in the manufacture of the lamp, are sealed into the base of the lamp so as to extend therethrough and into the globe of the lamp in a direction approximately longitudinally of the lamp and in a more or less sideby-side spaced relation. Outwardly of the lamp base the lead-in wires are provided with suitable terminal portions comprising open-ended wire loop contact members 22 respectively bent around the rounded end of the base to extend alongside opposite fiat surfaces thereof but terminating short of the grooves 18 therein.

Having described the particular type of flash lamp which the socket of the present invention is designed to accommodate, the socket construction will now be de scribed. Referring now to FIGS. 1 and 2, the socket constituting the present invention may be incorporated in a photoflash unit, including batteries, not shown, and the lamp socket contacts, to be hereinafter described, are electrically connected in circuit relation with a flash switch, indicated at S in FlG. 2, which may be closed by operation of the camera shutter to flash the lamp in timed relation with the opening of the shutter as is well known in the art.

The photofiash unit may comprise a box-like housing 25 molded from a suitable plastic material and having spaced parallel side walls 26 joined at the top by a top wall 27 and joined at the bottom by a socket compartment consisting of two spaced parallel walls 28 and 29, see FIG. 2. The front of this socket compartment is closed by a front wall 30, see FIG. 1, but is open at the rear side so as to be closed, along with the upper part of the housing, by a removable cover, not shown, which is detachably connected to the housing to permit replacement of batteries therein.

A metal reflector 31 of the form shown in FIG. 1 is assembled to the housing 25 by being slipped into the upper portion thereof from the rear when the cover is removed and moved forwardly until wing portions 32 on opposite sides thereof engage a vertical locating rib 33 on the inside face of each of the side walls 26. When the reflector isso positioned'against the locating ribs the curved portion 34 of the reflector is properly located with,

up'with, the inturned edges 36-at the front of the side walls to give a finished appearance tothe assembled unit. The reflector has a base portion 37 which will rest on 4, straight portion ofopposite lamp terminals 22 and frictionally holdthe lamp in the socket. This frictional grip,

plus the stabilizing effect of the upturned tabs 41 engaging the lamp globe, serves to firmly hold the lamp in an up top of, and extend substantially to the front edge of, the

uppermost wallv 28 of the socket compartment when the reflector isassembled into the housing as decribed. Any suitable means, i.e., rivets, cement,1 etc., may be used to hold the reflector in the described assembled relation in thehousingr The rear edge of the uppermostwall28 of the socket compartment may be provided with apair of 'arcuatecutouts 39, only one thereof being shown in FIG;

1, for vertically positioning a pairof small batteries, not shown, within the housing and in circuit relation with the socket contacts as will be described. Corning, now to the lamp socket construction, the uppermost wall 28 of the socket compartment is provided 'with an elongated opening 40 through which the base 12 serted axially, into the socket theends of these tabs 41 will engagethe tapered portions 16 of the lamp globe and will serve to both limit the insertion'of a lamp into the socket and at the same time stabilize the lamp in a vertical position after it has been inserted into the socket. While these stabilizing'tabs 41 may be formed up directlyfrom the uppermost top wall 28, it hasbeen found desirable to formthem up from the reflector materialwhich may be 7 highly reflectant stainlesssteel'so as toenablethe socket to withstand the rather high temperature that is encountered at the time of firing of the lamp andstill maintain intimate physical contact withthe tapered portions of the lamp globe in order toflstabilize the lamp inthe socket.

Within the socket compartment two socket contacts 43 and 44 of the form best shown in FIG. 1 aremounted between spaced walls 28 and29. Socket contact 43risv generally S-shaped and has a horizontal base portion 42 which rests upon the inner surface of wall 29 and is fas-f tened in place thereon by arivet, or like means not shown, passing through an opening 45 alongwith a rivet, or the like, passing through an opening 46 in an upturned wing 49 which will lie against the inside face of thefront wall 30. Extending upwardly from the base .portion 42 at an angle to the axis of opening .40 is a leg 47 which terminates in a bowedportion .48 which extends partially. across the opening 40 .to frictionally engage one of the terminals 22 on the base of the, lamp at a point above the bend therein when a lamp is inserted into the socket, as shown in,

right position in the socket. This is particularlytrue because the frictional grip provided by the socket contacts does nothave to overcome a spring ejector means as is normally provided in such sockets for the purpose of ejecting the lamp from the socket after it has been fired. In order to limit the-outward movement of each bowed portion 43 and 53 of contacts 43 and. 44, respectively, when a lamp isinserted into' the socket and thereby insure the maximum frictional grip on'thelamp base therebetween, the extreme'endsof each of the bowed portions 48kand53 are adapted to be forced against the edge of notches 60 formed in the wall 28 at each edge of opening terminal to 6.6 is terminal 68 turned down from contact 43],and extending through an openinginthe bottom wall of the housing. 'Whenthe photofiash unit is detachablyv mounted on the camera wall C in any known manner the terminals 66 and 68 will, engage corresponding terminals :66 and 68 on the-camera wallto connectlthe flash synchronizer .switch'S in the camera in controlling relation with the flash socket so that closing of this switch will fire pthe flashlamp. While wehave not shown it, a contact strap will beprovided in the photoflashunit housing 25 to connect those terminals of the. two batteries not engaging spring terminals62 andr64.f

, In order to selectively eject-a; flash lamp from the socket the bowed portion 53 of contact 44 is-moved from the solidjline position-shown in FIG.,2, which it, normally assumes by virtue of the resiliency of the metal-from which contact '44 is made, to the dotted line position.

-During this movement the long arm 51 andcross member 52 flex at the point tot. juncture .75 between the cross member ,52 and:theishort arm with the result, that the bowed portion 53 swings through .an are about junc- "ture 75 .as the pivot point. This means that-the bowed portion 53 of contact 44 moves downwardly of and toward the bowedpo rtion 48 of; contact;43;and in so moving =Wl11f squeeze the base of the lamp and. eject it Socket contact 44, which is generally U-shaped in form,

has a shortarm 50, along arm 51 normally substantially parallel thereto, and the two arms being joined by a cross member.52. The free end of the long arm '51 terminates in a bowed portion 53 which extends partially into .the

opening 40in opposition-to bowed portion 48 of contact I -43 and is offset therefrom to engage the straight portion of the other terminal 22 of the lamp above the bend therein. The contact 44 is fastened in the socket comfrom the; socket in much the same-imanner in which a watermelonfseed is propelled by; squeezing it between the thumb and forefinger. a

For selectively moving bowedportion 53 of contact 44 downwardly to. the dotted line position shown in FIG. 2 in order to eject the lamp, a lever:80 is'connect'ed at one end tolong; arm 51" and: the other end thereofextends .across the socket compartment and terminates in a turned over end81 which extends through a. slot 82 in the sidewall of the housing so asto be accessible forvma'nual depression." Due to thenormal resilience of contact 44- the'ejecting lever 80' normally assumes the solid line posi-.

' tion shown in FIG. 2 '1 border to'eject the lamp from the partment' by arivet, or the like, not shown, passing through a hole in the upturned wing 55 on arm 50 and which engages the front wall 30 of the socket, comlimit the axial insertion of the lamp ,into thesocket.

at FIG. 2, when a lamp is inserted into order to simplify fabrication we-have shown the lever-'80 formed as an integral part of contact 44 by being turned up from, and in, perpendicular relation to, one edge of long arm-'51., By such a construction strength is given p to lever to oppose flcxure thereof :since the downward In this position bowed portions 48 and 53 of socket contacts 43 and 44, respectively, will frictionally engage the pressure is being transmitted cdgewise rather than fiatwise thereof; From the above description it will be apparent that the socket construction we have devised requires a minimum number of parts and thereby involves a minimum in both fabrication and assembly costs. The contact members 43 and 4-4 are so designed that each of these two parts will include not only the lamp engaging contacts but also the necessary terminals and mounting means for fastening the contacts in the photoflash unit in the proper assembled relation, as well as also providing the lamp ejecting rneans. Despite the simplicity of this lamp socket construction it is capable of more securely and accurately holding an AG1 type flash lamp than an commercially available socket of which applicams are aware. The main reason why this socket construction is able to hold a lamp with such stability is that the lamp holding means does not have to overcome a lamp ejecting mechanism which is normally attempting to eject the lamp from the socket as is conventional practice. This also makes it much easier to insert a lamp into the socket because such insertion is not being opposed by a spring loaded ejecting mechanism. In addition to the provision of means on the socket for physically engaging the globe of a lamp to limit its insertion into the socket and stabilize it after it is inserted allows the operator to properly insert the lamp without thinking about how much pressure he should assert in this operation in order to be sure the lamp is properly seated and still not damage the socket contacts or the spring ejecting mechanism as found in conventional socket constructions.

Although we have shown and described certain specific embodiments of our invention, we are fully aware that many modifications thereof are possible. Our invention therefore is not to be limited to the precise details of construction shown and described but is intended to cover all modifications coming within the scope of the appended claims.

We claim:

1. A lamp socket for releasably retaining a flash lamp having a globe portion tapering to a flattened base, a first electrical terminal bent around and up one side of the end of said base and a second electrical terminal bent around and up the other side of the end of said base, said socket comprising in combination (A) a wall provided with an elongated opening adapted to accommodate the flattened base of said lamp when the lamp is inserted axially therethrough,

(B) means on opposite sides of said opening and extending upwardly from said wall to engage the tapered portion of the globe of said lamp to limit its insertion into said elongated opening and to stabilize the lamp in said socket,

(C) a first fixed electrical contact extending partially across said opening to frictionally engage one electrical terminal on said lamp base above the bent portion thereof when a lamp is inserted into said Opening,

(D) a second electrical contact extending partially across said opening from the other side thereof and movable from a normal position, in which it frictionally engages the other lamp terminal above its out portion and substantially in direct opposition to said fixed electrical contact, to a lamp ejecting position during which movement it moves down the bent portion of the lamp terminal it engages and toward said fixed contact to eject the lamp from said opening, and

(E) means for selectively moving said second Contact from its normal to its lamp ejecting position to eject a lamp from the socket.

2. A laznp socliet according to ciais. 1 including a metal reflector having a portion engaging said wall, and in which said means exte ding upwardly from said wall to engage the apered portion of the globe of said lamp to stabilize the lamp in said socket comprises two tabs turned up from said portion of said reflector at opposite sides or" said opening.

3. A lamp socket according to claim 1, in which said last mentioned 1'. cans comprises a pivoted lever movable between a normal position and a lamp ejecting position, and means connecting said lever to said second contact whereby movement thereof to its lamp ejecting position rnoves said electrical contact from normal position to its lamp ejecting position.

4. A lamp socket for releasably retaining a ill-sh lamp having a globe portion tapering to a flattened base, a first electrical terminal bent around and up one side of the end of said base and a second electrical terminal bent around and up the other side of the end of said base, said socket comprising in combination (A) a pair of spaced and substantially parallel walls,

(1) one of said walls provided with an elongated opening adapted to accommodate the flattened base of said lamp when the lamp is inserted axially therethrough,

(B) means on opposite sides of said opening and exending upwardly from said one wall to engage the cred portion of the globe of said lamp to limit its insertion into said opening and to stabilize the lamp in said socket,

(C) a fixed electrical contact supported on and extending upwardly from said second wall and including a bowed portion adjacent its free end extending partially across said opening from o side thereof to frictionally engage one electrical terminal on said lamp base above the sent portion thereof when a lamp is inserted into said opening,

(D) a substantially U-shaped contact strap made of resilient metal and mounted with one arm thereof engaging said second Wall, the cross arm thereof extending substantially perpendicular to said walls and offset from said opening and said second arm thereof normally lying against said first wall and texts .ding to a point adjacent and below said opening,

(E) a second electrical contact formed up as a bowed portion on the end of said second arm and which in the normal position of said second arm extends partially across said opening in opposition to said first contact to frictionally engage the other lamp erminal above its bent portion to hold the lamp in the socket, and which moves downwardly and inwardly of said bent portion of the engaged lamp terminal to eject the lamp when said second arm is l'lexed toward said first arm, and

(P) an elongated lamp ejecting lever fixed to said second arm and extending across said opening to a point where it is manually accessible for selectively flexing said first arm and second contact thereon from a normal position toward said second wall to eject said lamp from the socket.

Vroorn et al. Apr. 18, 1961 Kenichi Kawatc May 16, 1961 

1. A LAMP SOCKET FOR RELEASABLY RETAINING A FLASH LAMP HAVING A GLOBE PORTION TAPERING TO A FLATTENED BASE, A FIRST ELECTRICAL TERMINAL BENT AROUND AND UP ONE SIDE OF THE END OF SAID BASE AND A SECOND ELECTRICAL TERMINAL BENT AROUND AND UP THE OTHER SIDE OF THE END OF SAID BASE, SAID SOCKET COMPRISING IN COMBINATION (A) A WALL PROVIDED WITH AN ELONGATED OPENING ADAPTED TO ACCOMMODATE THE FLATTENED BASE TO SAID LAMP WHEN THE LAMP IS INSERTED AXIALLY THERETHROUGH, (B) MEANS ON OPPOSITE SIDES OF SAID OPENING AND EXTENDING UPWARDLY FROM SAID WALL TO ENGAGE THE TAPERED PORTION OF THE GLOBE OF SAID LAMP TO LIMIT ITS INSERTION INTO SAID ELONGATED OPENING AND TO STABILIZE THE LAMP IN SAID SOCKET, (C) A FIRST FIXED ELECTRICAL CONTACT EXTENDING PARTIALLY ACROSS SAID OPENING TO FRICTIONALLY ENGAGE ONE ELECTRICAL TERMINAL ON SAID LAMP BASE ABOVE THE BENT PORTION THEREOF WHEN A LAMP IS INSERTED INTO SAID OPENING, (D) A SECOND ELECTRICAL CONTACT EXTENDING PARTIALLY ACROSS SAID OPENING FROM THE OTHER SIDE THEREOF AND MOVABLE FROM A NORMAL POSITION, IN WHICH IT FRICTIONALLY ENGAGES THE OTHER LAMP TERMINAL ABOVE ITS BENT PORTION AND SUBSTANTIALLY IN DIRECT OPPOSITION TO SAID FIXED ELECTRICAL CONTACT, TO A LAMP EJECTING POSITION DURING WHICH MOVEMENT IT MOVES DOWN THE BENT PORTION OF THE LAMP TERMINAL IT ENGAGES AND TOWARD SAID FIXED CONTACT TO EJECT THE LAMP FROM SAID OPENING, AND (E) MEANS FOR SELECTIVELY MOVING SAID SECOND CONTACT FROM ITS NORMAL TO ITS LAMP EJECTING POSITION TO EJECT A LAMP FROM THE SOCKET. 